It is now possible to create user accounts on the Kindle device itself, thanks to a software upgrade. The updated Kindle software, version 3.0.1, is already being made available and will ensure a completely untethered digital reading experience with the Kindle.
So after you have installed the upgrade you will be able to create an account with Amazon, browse the online catalog of books as well as buy e-books, and manage e-book purchases efficiently. All this without requiring access to a computer. The upgrade will be transferred to the Kindle devices over-the-air and while it can also be downloaded from the Amazon site, doing such a thing will however kill the untethered experience in the first place.